π‐complexes of diborynes with main group atoms

We present herein an in‐depth study of complexes in which a molecule containing a boron‐boron triple bond is bound to tellurate cations. The analysis allows the description of these salts as true π complexes between the B−B triple bond and the tellurium center. These complexes thus extend the well‐known Dewar‐Chatt‐Duncanson model of bonding to compounds made up solely of p block elements. Structural, spectroscopic and computational evidence is offered to argue that a set of recently reported heterocycles consisting of phenyltellurium cations complexed to diborynes bear all the hallmarks of π‐complexes in the π‐complex/metallacycle continuum envisioned by Joseph Chatt. Described as such, these compounds are unique in representing the extreme of a metal‐free continuum with conventional unsaturated three-membered rings (cyclopropenes, azirenes, borirenes) occupying the opposite end

Mild synthesis of diboryldiborenes by diboration of B–B triple bonds

A set of diboryldiborenes are prepared by the mild, catalyst-free, room-temperature diboration of the B–B triple bonds of doubly base-stabilized diborynes. Two of the product diboryldiborenes are found to be air- and water-stable in the solid state, an effect that is attributed to their high crystallinity and extreme insolubility in a wide range of solvents

Isolation of diborenes and their 90°-twisted diradical congeners

Molecules containing multiple bonds between atoms—most often in the form of olefins—are ubiquitous in nature, commerce, and science, and as such have a huge impact on everyday life. Given their prominence, over the last few decades, frequent attempts have been made to perturb the structure and reactivity of multiply-bound species through bending and twisting. However, only modest success has been achieved in the quest to completely twist double bonds in order to homolytically cleave the associated π bond. Here, we present the isolation of double-bond-containing species based on boron, as well as their fully twisted diradical congeners, by the incorporation of attached groups with different electronic properties. The compounds comprise a structurally authenticated set of diamagnetic multiply-bound and diradical singly-bound congeners of the same class of compound

Strained <i>ansa</i> Half-Sandwich Complexes of Ruthenium and Osmium and a Non-Iron Metallopolymer by Ring-Opening Polymerization

Herein we report the first non-iron polymer obtained from an <i>ansa</i> half-sandwich complex. This polymeric organometallic material was obtained from a new disilanediyl-bridged ruthenium complex upon thermally induced ring-opening polymerization (ROP). Additionally, a corresponding distannanediyl-bridged osmium species is reported, the first example of an <i>ansa</i> half-sandwich complex of this element

Exclusive p encapsulation of light alkali metal cations by a neutral molecule

Cation-p interactions are one of the most important classes of non-covalent bonding, and are seen throughout biology, chemistry and materials science. However, in almost every documented case, these interactions play only a supporting role to much stronger covalent or dative bonds, making examples of exclusive cation-p bonding exceedingly rare. In this work, a neutral diboryne molecule is found to encapsulate the light alkali metal cations Li+ and Na+ in the absence of a net charge, covalent bonds, or lone-pair donor groups. The resulting encapsulation complexes are to our knowledge the first structurally authenticated species in which a neutral molecule binds the light alkali metals exclusively through cation-p interactions

Isolation of diradical products of twisted double bonds

Molecules containing multiple bonds between atoms—most often in the form of olefins—are ubiquitous in nature, commerce, and science, and as such have a huge impact on everyday life. Given their prominence, over the last few decades, frequent attempts have been made to perturb the structure and reactivity of multiply-bound species through bending and twisting. However, only modest success has been achieved in the quest to completely twist double bonds in order to homolytically cleave the associated π bond. Here, we present the isolation of double-bond-containing species based on boron, as well as their fully twisted diradical congeners, by the incorporation of attached groups with different electronic properties. The compounds comprise a structurally authenticated set of diamagnetic multiply-bound and diradical singly-bound congeners of the same class of compound